OBJECTIVE: To assess the effect of advancing age upon bone mass as measured by dual energy x-ray absorptiometry. RESULTS While age-related bone loss in humans is well established, the effect of advancing age upon bone density in non-human primates is not. We have previously been unable to demonstrate "age-related" loss cross sectionally. It is possible that this is the result of the standard laboratory chow diet which is very high in calcium and vitamin D by human standards. FUTURE DIRECTIONS We will assess age related skeletal changes in bone mass and markers of bone turnover in this cohort of older female monkeys to document the presence or absence of "age-related" bone loss. Keywords Osteoporosis, bone density, bone strength Funding Geriatrics section discretionary funds